Poor idling Astra 94 1.8 16v ecotec - Defiant
Hi,

I have had a idling problem with my astra 1.8 16v ecotec cdi.It was idling very low, causing a very lumpy idle. I was told the cause was most likely the \'idle control valve\'. I replaced this at cost of nearly £150 and unfortunately this has not completely cured the problem as now it idles too high. Often between 1000-1400rpm at idle.It also hunts between 1000-1400 occasionally.
Another note to consider is that when I pull off the plug that connects to the \'Idle control valve\' it makes no difference. As if there is no signal going to it in the first place leading me to believe that the new \'Idle control valve\' isnt doing anything yet.
If anyone could shed some light on this I would be most grateful.

Regards Carl
Poor idling Astra 94 1.8 16v ecotec - Adam Going (Tune-Up)
Hi Carl,

Plenty of discussion on this in the archives here.

Vital to clean throttle housing and carankcase breather system (especially the vacuum port into the inlet manifold below throttle housing) when fitting new ISCV. Base throttle position and Throttle Position Sensor may than require adjustment.

Regards, Adam


Whatever is rightly done, however humble, is noble.
Poor idling Astra 94 1.8 16v ecotec - Defiant
Adam,

Cheers for your advice. Ill either clean this my self at the weekend or get one of my local garages to do the adjustments for me(probably better that way)
Appreciate the quick response.

Regards Carl
Poor idling Astra 94 1.8 16v ecotec - Defiant
One other thing, you didnt mention about the fact that when I pull of the plug from the ISCV it made no difference. Does that infer that there could be no signal getting to the sensor in the first place or is this normal. Is there a test I can do to check if sensor is working ok?

Cheers Carl
Poor idling Astra 94 1.8 16v ecotec - Adam Going (Tune-Up)
Carl,

Could be that the throttle base setting is way out. Signal to ISCV can only really be checked using oscilloscope.

Adam
Whatever is rightly done, however humble, is noble.

 

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